The invention relates to a flexible strip comprising at least one optical fibre for carrying out deformation and/or temperature measurements in or on a civil engineering structure.
It aims in particular to locate and measure disruptions such as deformations and/or temperature variations in or on civil engineering structures. Such measurements are generally conducted over long periods of time in order to determine, for example, whether the structure is suffering damage and is at risk of deterioration; these tests or measurements enable precautionary monitoring, particularly for predictive maintenance.
In known prior art devices, optical fibres are placed in or on a surface of a structure to be monitored, in order to obtain measurements in situ. These optical fibres generally have a diameter of between 80 and 500 μm, and in particular about 150 μm, comprising a central portion consisting of a core and cladding which are capable of allowing light to propagate and at least one protective sheath.
However, the integration of such optical fibres in or on a civil engineering structure does present disadvantages. These optical fibres are fragile and can be damaged during placement or later on by the stresses they are exposed to (shear stresses, undesired bending of the fibre). In certain cases they may deteriorate over time, particularly in “hostile” environments where there is a risk of penetration of water or alkaline ions, for example followed by prolonged contact with such a “hostile” environment.
An object of the invention is to propose a device which allows determining locations and measurements of deformation and/or measurements of temperature for a structure, i.e. a civil engineering structure or a portion of a civil engineering structure, which prevents the above disadvantages. Another object of the invention is to provide such a device for a reasonable cost and to allow easy installation in the structure.